Novavax has commenced administering the initial booster doses of its protein-based Covid-19 vaccine, NVX-CoV2373, in the paediatric expansion of the Phase III PREVENT-19 clinical trial. 

The trial will assess the safety and immunogenicity of a third dose of the vaccine in adolescent trial subjects of the age 12 to 17 years. The company anticipates reporting preliminary data from the trial during the second half of this year.

All the subjects in PREVENT-19 of this age group are now eligible to receive a third booster dose of the vaccine.

The booster vaccine is similar to the active vaccine of 5μg of recombinant spike protein plus 50μg of Matrix-M adjuvant given earlier to the subjects under a two-dose series. 

Furthermore, the booster is intended to be given a minimum of five months following the administration of the active vaccine. 

Analysing the humoral immune response 28 days following booster dose administration and describing Covid-19 disease are the post-booster goals of the trial. 

Created from the genetic sequence of the SARS-CoV-2 virus’ initial strain, the vaccine has purified protein antigen.

The vaccine is formulated with the company’s saponin-based Matrix-M adjuvant and cannot replicate or cause Covid-19 infection.

Novavax Research and Development President Gregory Glenn said: “We see the ongoing need for alternative vaccine options because we are continuing to monitor spikes in Covid-19. 

“The expansion of our PREVENT-19 booster trial into the paediatric population reinforces our commitment to seek to make our vaccine available to a broader population.”

In March this year, the company reported that NVX-CoV2373 will be assessed as a booster in two clinical trials.